1. Field of the Invention
The invention pertains to a pressure switch with a pressure connection, with an electrical pressure sensor to generate a pressure-dependent electrical signal, with an operator-device and/or an adjusting device to input at least one pressure switch threshold and with at least one electrical switch output.
2. Description of the Prior Art
In known pressure switches the desired switching pressure is adjusted, for example, by means of an adjusting screw or an adjusting potentiometer. More complicated, known solutions feature operator keys and a display, and by means of the operator keys, the desired switching pressure can be programmed, since, for example, the desired pressure value is input as a numeric value. However, in these known pressure switches, the specification of the switching pressure is in general cumbersome and complicated to carry out.
One problem of the present invention consists in creating a pressure switch in which the desired switching pressure can be specified in a simple and yet still variable manner.
This problem is solved according to this invention, in that the pressure switch can be adjusted by operation of the operator device in such a manner that the electrical signal corresponding to the instantaneously applied pressure is saved as the first saved pressure value and the electrical signal corresponding to a pressure applied temporally thereafter, is saved as a second saved pressure value, where these two saved pressure values define the pressure switching threshold(s) in the operating mode.
In the pressure switch according to this invention, a saved pressure value can be quickly and easily saved, for example, by operation of an operator key or an operator key combination. The input of a numeric value or the setting of an adjusting screw or of a potentiometer is no longer necessary. The particular, applied pressure is taken in this case as a saved pressure value. It proves to be particularly favorable to use two temporally sequential, applied pressures as saved pressure values, in order to specify the pressure switching thresholds in a particularly variable manner.
Favorable refinements and improvements to the pressure switch as described in claim 1 are possible by means of the modifications stated in the subclaims.
The saved pressure values can be saved, preferably by repeated operation of the operator key or of an operator key combination. It has proven to be particularly favorable in this case, that after the first or initial operation, a prompt will appear on a display for an additional, or repeated, operation, or by means of an acoustical and/or optical signal, in particular by means of a light emitting diode. Thus, the operator will be reminded that an additional operation is required.
Alternatively, the saving can also take place by means of one-time operation, and then after a specified time the applied pressure will be accepted as a second, saved value.
The operating key combination consists preferably of an operator key allocated to the switch output, and a program key which is needed anyway in most cases, so that no additional keys are needed.
To achieve a greater variability and to achieve more variable potential applications, the pressure switch has preferably several mutually independent switch outputs, for which two saved pressure values are provided for the save. To each switch output, preferably one operator key is provided.
In addition to its function for saving of the saved pressure values, the operator key is designed in a favorable manner to trigger the display or replay of the value of the switch threshold(s) of the allocated switch output by means of a display or of an optical and/or acoustic signal, in particular of a light emitting diode, so that in particular, different types of operation or differing activation combinations with other operator keys trigger the differing functions of the save and of the display. Different operating modes of this type, can consist for example in that the particular operating key can be operated for different time lengths or in a differing sequence.
To specify the differing operating modes as a function of the saved pressure values, in a favorable manner at least one adjusting and/or programming key is provided. The pressure switch can be used in a highly variable manner, in this case. Preferably in an operating mode as a threshold value switch, the average value of the saved pressure values can be specified as the switching threshold. In one additional operating mode as hysteresis switch, the two saved pressure values can be predefined as on/off switching thresholds. Thus initially, three differing operating modes can be selected. In addition, if a reversing switch is provided for the switch outputs between open mode and closed mode, then a total of six different operating modes can be selected, which all depend on the two saved pressure values.
To specify the desired operating mode, a menu prompt on a display is suitable.
One design example of the invention is presented in the figures, and this example will be explained in greater detail below.